Project Summary Behavioral sleep problems such as sleep onset difficulties, night wakings, and inadequate duration affect 25-40% of 2.5 to 5 year-old children. Here, we propose a randomized controlled trial and longitudinal follow- up of a health behavior change intervention that aims to give parents knowledge and skills, and motivate them to set goals, problem-solve, and improve their child's sleep. Previous interventions have largely focused on a single aspect of sleep (such as bedtime resistance) and utilized a single tactic (such as graduated extinction). Despite the availability of these strategies, parents often struggle to address their child's sleep problems, which may stem from multiple factors including an inconsistent bedtime, a bedtime routine that is a poor match for the child's temperament, variable parental responses to child behavior, and social and environmental barriers. As a result parents may need to be coached in how to make multiple changes in bedtime behaviors, and without active support, may give up on worthwhile changes before reaching the tipping point where positive outcomes are seen. To better address the multifactorial nature of early childhood sleep problems, the successfully pilot-tested SHIP (Sleep Health in Preschoolers) intervention offers parents education and tools utilizing evidence-based strategies. Short-term consequences of sleep problems in young children include behavior problems and parental stress and sleep loss. In the long-term, observational studies have associated early childhood sleep problems with obesity, mental illness, and poor academic achievement. Causal evidence regarding these long-term effects can provide the motivation and evidence needed to make early childhood sleep a public health priority. Using an innovative and multi-faceted approach to child sleep, we will leverage the experimental nature of a RCT design to test the causality of the relationship between early childhood sleep problems and subsequent obesity, emotional and behavior problems, and poor academic achievement. While understanding the long-term outcomes of poor sleep in early childhood is vital to improving health, even acute behavior problems and parental sleep loss highlight the need for effective and accessible interventions. As such, our specific aims are as follows: 1. To test if the SHIP program can significantly improve sleep in intervention preschool children as compared to active controls, both following intervention and at follow-up. 2. To test whether intervention for early childhood sleep problems leads to decreased long-term sequelae (excess weight gain, emotional and behavioral problems, and poor school achievement) in the intervention group as compared to active controls. 3. To explore how intervention in early childhood affects the trajectory of sleep problems and family response to re-emergent sleep problems over 3 years. Achieving these aims has the dual potential to improve child sleep and expand our scientific understanding of how early childhood sleep problems affect development.